This invention relates to a system for air conditioning leak prevention and leak containment. This invention specifically relates to apparatus and method for pooling non-cycling refrigerant fluid away from the compressor, for lubricating a portion of a non-cycling AC system, for providing an improved high pressure relief valve having indicating means and a trap for containing the refrigerant fluid formerly discharged to the atmosphere.
Chlorofluorocarbons, or CFCs, are manmade chemicals that have been linked to the possible depletion of the earth's protective ozone layer. CFCs have been widely used as refrigerants for conditioning air and preserving food and medical supplies, among other uses.
Before scientists learned about the possible danger to the ozone layer posed by CFCs in the atmosphere, and because CFCs were cheap, replacement of CFCs rather than prevention of leaks in the air conditioning and other refrigeration systems, (hereinafter AC systems) was the method for dealing with malfunctioning AC systems. Since recognition of released CFCs as a problem there have been many attempts to monitor leaks. Most of these attempts have been chemical in nature, e.g., a replacement chemical for CFCs.
An international agreement, called the Montreal Protocol, calls for a total phaseout of ozone depleting substances, including CFCs, in developed countries. This will result in a total phase-out of production and consumption by Jan. 1, 2000. Currently, the protocol disallows leaks to the atmosphere. Additionally, under the Montreal protocol, one cannot re-charge a leaking system with refrigerant.
There have been attempts to replace CFCs with ozone-friendly chemicals. Unfortunately, none of these CFC replacements seem to work as well as CFCs at cooling. Some are even dangerous, causing a fire hazard. However, even if efficient and safe CFC replacements are developed, it would be an advantage to contain these chemicals and prevent their escape to the atmosphere, whether it be to protect the atmosphere to prevent escape of costly chemicals, or protect the user.
Of the many AC system/refrigeration system leak monitors available, there are generally those that detect the refrigerant outside of the system, those that detect air within the system and those that measure the amount of refrigerant flowing through the system.
The external refrigerant detection means include use of dyes, either visible or fluorescent, that indicate the source of leak of refrigerant out to the atmosphere.
An example of the second type of monitor systems is an air detecting monitor as found in Havemann, U.S. Pat. No. 4,890,459. This type of monitor detects the presence of oxygen in the AC system thereby indicating a leak. Havemann also provides for system shutdown if the leak continues for a predetermined period of time.
A third type of art teaches a flow monitor that measures the amount of refrigerant flowing through the AC system. When the amount of refrigerant measured falls below a certain predetermined level, the refrigerant is pooled, and an alarm is actuated. Another flow monitor utilizes a low pressure cut-off switch that precludes the operation of an AC system should the pressure to too low. The problem with this method is that by the time the pressure is low enough to activate the pressure cut-off switch, up to a large percentage of the refrigerant has already escaped into the atmosphere. The switch is used to protect the AC unit, not protect the atmosphere.
The chemicals making up refrigerant fluid, in addition to CFCs, contain a lubricant. The purpose of the lubricant is to prevent drying of seals contained by the AC system. Dry seals are more prone to leaking.
Experience has shown that, especially with the AC system used in a motor vehicle, a substantial amount of refrigerant is lost during the time the system is not running, especially during lengthy seasonal periods of time. During the seasonal "down" time, seals contained within the system are more prone to drying, because the refrigerant is not being cycled through the system, and the seals therefore become less effective. Some motor vehicle models cycle the compressor whenever the defrost function is activated. A problem with this art is the effectiveness is limited because long periods of time can elapse before the defrost function is required, cycling refrigerant, thus allowing the seals to dry.
Manually actuating cycling of the AC system during "off season" would not be an efficient solution to the problem of dry seals. Cycling the AC increases fuel consumption, and it would be haphazard at best for a consumer to attempt regular cycling of the AC system. Additionally, cycling the AC increases wear and tear on the AC system components.
Another problem is that currently, high pressure relief valves are used, exhausting refrigerant to atmosphere, as a protective measure to prevent build up of high pressure within the AC system. These current high pressure relief valves give no indication if seepage occurs or any indication that a high pressure event has occurred.
Additionally, when the AC system is found to be lacking refrigerant, the current high pressure relief valve gives no indication as to what kind of problem has occurred, whether the missing refrigerant leaked out through an unspecified area or through the high pressure relief valve. Current high pressure relief valves can seep refrigerant to atmosphere due to old age of the valve.
For the foregoing reasons, there is a need for a cost-effective mechanical system to provide continued use of CFCs while at the same time protecting the ozone layer of the atmosphere. The embodiments of this invention provide means for protecting the atmosphere, specifically, the ozone layer, either with the continued use of a known beneficial group of chemicals or other man-made refrigerant chemicals.